In the preparation of sweets with a sour taste (for example, sour hard candy or fruit drops ), caramels, jelly fruit, marshmallows, jelly beans, chocolate candy fillings and acidulated suckers so-called buffered acids are preferably used in order to obtain on the one hand an agreeable, acidulous taste and, on the other hand, to avoid disagreeable side-effects of an acid additive, such as inversion of the saccharose as well as hydrolytic degradation of gelatin or other polymeric thickeners. On the other hand, such solutions must be as concentrated as possible in order to exclude hydrolytic effects as far as practicable; on the other hand, it is necessary to keep them sufficiently liquid, so that they can be pumped in the course of the modern continuous manufacturing methods. A known product often used for such purposes is the so-called buffered lactic acid, which is an aqueous mixture of lactic acid and sodium lactate having a dry substance content of about 75 to 80% and an average pH-value of 2.7 to 3.2 preferably of 2.9 to 3.0. As a liquid acid with a lesser tendency toward inversion than, for example, tartaric or citric acid, lactic acid comes closer to the requirements to be fulfilled, i.e. that it may be pumped easily and has a low hydrolytic effect. However, its disadvantage is its relatively mild acidulous taste, as well as its higher price.
Therefore, it has already been tried to produce a cheaper buffered lactic acid with a more pronounced and more refreshing taste by adding to it more or less large quantities of solid edible organic acids (for example, tartaric or citric acid). However, when more than 5% of such acids were added, crystalline precipitations resulted which substantially interfered with the processing of the buffered lactic acid, because the concentration of the acid solution was changed in an uncontrolled manner, the pumps were plugged up, crystal agglomerations could form in the candy.
In order to solve this problem, it has also already been proposed to produce concentrated stable solution of solid edible acids by thoroughly admixing the solid edible acids alone, or together with buffered salts with polvalcohols comprising up to 30% of water, heating the mixture quickly to temperatures from 80.degree. to 150.degree. C. and cooling it quickly as well (see German Offenlegungsschrift No. 21 20 846.8-42). The low ester quantities formed thereby were intended to prevent crystallization. But, in practice, this process has also proved not to be fully satisfactory (due to excessively high inversion rates upon use of the product thus obtained). Besides, the product becomes even more expensive due to the required addition of Polyalcohol and the additional process step.